Fifth wheel construction



0t.23, 1945. G. WALTHER ETALA, 2,387,625

FIFTH WHEEbL CONSTRUCTION Filed Aug. 3,"l943 GEORGE WALTHE-R ELMERADMILLER 8% Y j Patented Oct. 23, 1945 FIFTH WHEEL coNsTRUcTroN George Walther, near Dayton, and Elmer L. Mili-` er, Dayton, Ohio, assgnors to The Dayton Steel Foundry Company, Dayton, Ohio, a corporation of Ohio Application August 3, 1943, Serial N o. 497,2,48

l6 Claims.

The present invention relates to the construction and operation of coupling devices such as employed for connecting a tractor or truck unit and a trailer or semi-trailer. This type of mechanism is well known and is used in many forms, the present application showing the manner in which the invention is incorporated in and applied to one type of fifth wheel construction.

One of the principal objections to trailer couplings such as now widely employed is that it is very diicult for the truck operator before start-J ing the truck to determine whether the truck and trailer are properly connected. This is due to the fact that the kingpin on the trailer cannot be seen by the operator after the tractor is under the trailer. Much time is often lost and the load or equipment damaged because the operator may start up the truck unit before the kingpin is properly coupled.

It is the object of the invention to construct and combine with a fifth wheel construction of any standard or accepted design a telltale de- .vice by which the operator may readily determine that the two units are coupled before starting up the truck. t

In the drawing and description there is illustrated one standard form of fifth wheelconstruction in which the invention is incorporated,

but it will be understood that the invention may readily be incorporated with any other type of coupling, the necessary changes or modifications to adapt the invention to other forms of couplings being within the skill' of any mechanic. It is also obvious that other changes and adaptations of the invention may be made within the scope of the invention as set forth in the appended claims.

In the drawing in which the best known or preferred form of the invention is shown:

Fig. 1 is a plan view of a coupling or fifth wheel construction in which a portion of the base or platform of the coupling is broken away to show the'underlyng parts, the kingpin being indi-,-`

cated as in its proper coupled relation;

Fig. 2 is a section on the line 2--2 of Fig. 1;

Fig. 3 is a view showing the locking member Withdrawnand the kingpin in coupling relation, as the parts are positioned prior to uncoupling;

Fig. 4 is a view showing the same parts with the kingpin only partially seated, at which time the telltale will indicate the improper seating of the kingpin;

Fig. 5 is a side elevation of a truck and trailer properly connected; and

Fig. 6 is a detail of lthe switch associated with the telltale.

In the drawing, l represents any standard form of truck or tractor unit having a platform 2 on which the fifth wheel unit, indicatedb'y the numeral 3, is attached. Thetrailer 4 of any de- .sired type is provided with the usual kingpin 5 attached to its forward floor 6, this pin being provided with a reduced portion 8 which directly engages the jaws of the coupling device.

The fifth wheel includes the platform or base I0 which is pivotally mounted at l2 on supporting brackets I4 attached to the platform. When there is no load on the fth wheel the platform l0 will tilt so that the truck may be backed under the forward end of the trailer.

The base or platform l0 is provided with an opening l5 the walls of which converge from the rear of the plate to a central slot I6 beneath which are located the two pivoted jaws I8 and I9 which constitute the coupling elements. 'I'hese jaws are pivoted at I8.a and 19a, respectively, to the under side of the base l0. These jaws close about the kingpin when it is properly seated and are provided with flaring, guiding surfaces` which lead to the central opening 20 between'the jaws into which the reduced central portion 8 of the kingpin fits.

.As the kingpin, moving in the direction of the arrow, enters the slot I6, as shown in Fig. 4, it moves into the opening 20, and the Ycontinued backward movement of the `truck causes the kingpin to strike the jaws which close about the kingpin into proper coupling relation, as shown in Fig. 1. v

Inl order to lock the jaws about the kingpin, there is provided a locking plunger or bolt 24 which is movable to locking position between shoulders 25 formed on the front ends of the jaws as shown in Fig. 1. This locking plunger is mounted for sliding movement over a pin 2:1 carried on the under side of the base and entering a slot in the plunger. The opposite end of the plunger is provided with anv elongated guiding Vpin 29 which is movable in a hole formed in a web Suasfthe forward end of the base plate I0. A locking plate or latch 32 is mounted on the base so that it can be moved over the end of the pin, thus insuring that the plunger is not accidentally withdrawn after the coupling operation is completed. A spring 33 surrounds the pin 2B and lies -between the web 30 and the head of the plunger and tends to force' the plunger against the forward ends of the jaws and then to its locking position when the jaws are closed. On the plunger 24 is provided a tailpiece 35 which is slotted to receive an operating lever 36 pivoted to the base plate at 31 so that by moving the leverl to the left, as shown in Fig. 3, the locking plunger is withdrawn and the coupling jaws are free to move so as to release the Kingpin as it moves in the direction of the arrow in Fig. 3 while the tractor is driven forward to uncouple the trailer, I K

In order` toi hold the! locking plunger'24 inlits withdrawn position' against the force ofthe spring 33 so that the jaws will be free to move, one side of the plunger is provided with an elongated notch or recess, the forward end of whichds! engaged when the plunger is fully withdrawn by the end of a pivo-ted latch 40 mountedon' the base" plateN and moved toward locking positionb'y. the coiled'. spring I2l The opposite end of the latch lies in the path of a pin 44 on the coupler jaw I9. As

` the Kingpin 5 spreads the jaws-z|-8 and I9 during' uncoupling, the pin 44 will strike the latch 4I); releasing the plunger 24 which will rest upon the ends of tl'lejavv'sy holdingthem inopen position until they arevclosed by the' entering movementof-the Kingpin, whereupon the spring! 33 will move it-into its lockedy position,

As-will be seenfthelmoving parts of the cou` pling are all concealed within thefifth wheel construction and the operatoris unable to de termine whetherr the coupling is properly made. beforehe moves the truck Topreventthe occurrence ofaccident'sby premature forward movement' of the tractor,v there is providedy al device which will not only indicatewhen thepinr Eris-improperly seated, as,` for example, in the position of the parts-asshown inIg. 4; butwill also indicate anymovement of` the yjaws I8 and I3A bythe Kingpin.v Thisl telltale will indicate that-the jaws aref'ullyf closed. Thus, except asi aresult of inattentiononthe par-t of the operator, the tractor will `noti` be started uprwhenthe kingpin isLw-holly outside ofthe jaws or partially en@ tered. The arrangementanddesignof the parts,

Y spreadiapart by the Kingpin as it is withdrawn therefore, constitute a simple, but alsoA a ver-y' effective device for the' purposesVv setforthl While the'safety device'ma'y be' incorporated in*V al number of embodiments# of the: invention, inthe preferred form shown an electric-switchboxl 50i is attachedto the underside ofj the-base plate mi having a=. springeactuated pin` 5 I which,` is so5 located: thatl when; the jawsv are` fully closed, thepinV is`-` moved; inwardY byY one of thevjaws, here shownas the jaw I8;- Thiswillclosey the openl switch` 512i within the box` and will light a telltale lamp 54 at some convenient point, preferably the instrument panell of the' tractor I.. When,fhow ever, the jaws are spread, the jaw I8` is with drawnfrom the' pin 5I which moves so thatethe switch isopen and-the light extinguished;

In makingthe. coupling or. hitch, the operator,- asihe backs the truck unit underthe trailer, will. watch the light which isy extinguisheduntil thejaws close about the* pin..

Itis possible without entirely defeating'4 the objects ofthe'inventonltohavethe telltale lightv glow, when`V the jaws are spread apart, butfthiswould` cause the light to be on during the entire: time that'the truck is idle. The: reverse operai tion,Y as? described above; is` preferred` fori` ifthe" from the jaws and to close about the Kingpin when'thecoupling'i'silly made, an alarm device, andlanelectric switch connected to the alarm device located; the path of one of said jaws and directly actuated thereby.

2: Ina trailertractor provided with a fifth wheelconstruction, a Kingpin, a pair of movable coupling jaws adapted to be spread apart by the kingpinas it-isl withdrawn'y fromV the jaws and-to close aboutthe Kingpin` when thecoupling is'l fully made, andi an alarmi dev-icelocatedin the cab/of thetrailer-t'ractorandhaving an operatv ingmeanslocated within the-path of one of said* jaws Landactuateduponth'e entranceof the king# pinAl between the jaws;-

3. Inadevice of the character'setforth a truck.

and' a-trailer, aL iifthwheel` onthe truck and a between which'V the Kingpin is'received-when the vehiclesare coupled, a-lamp-on the truck havingf av circuitand aI switchn in said circuit, saidy switchA being mounted adjacent oneofsaid-jaws andop erated'f by thevv movement thereof .A

4i In a devioe'of the-character setforth, aI truck' andl a trailer, a fifth' wheel on the truck and a Kingpin on the trailer, afpair'of jaws-on the truck between which the Kingpin is received when the vehicleslare'coupled, a1- lamp on the-truck having al circuit Van'd ai springI switch in said circuit,`V saidsw'it'ch' being mounted adjacent one off saidjawsan'din contact*withthejaw-I when the latter-'is closed! upon thekingpin' wherebysaidcircuit'is closed only when the jaws are closed.

5:-1'11 afth wheel'- construction', ai Kingpin, a movable coupling` jaw actuated'Y by the Kingpin asith'ecoupling islbeing made, and an alarm-septrailer arefiin coupled relation, af-king` pinion the trailer;- a pair of movable locking jaws on the fifthwheel, saidfjaws being movedb'y the Kingpin when theL truck andthe trailerare bei'ngfbroughtintov coupling relation andclosing abouttheking i pin to couple' the truck and thet'railerg-an electric'l lamptonJ the* truck, a switch y forv saidlampAv locatedw on'-V the fifth wheel, the switch being" responsiveto the positionoftheijaw's and` actuated directlyl by the; movement thereof to light or.' extinguish theilamlp.

Y GEORGE WALTHER..`

ELMERf-I'.k

Kingpin' on-the trailer; aupa'irV ofjaws vonthe truck. 

